Struct SemaphoreHandle 

pub struct SemaphoreHandle(/* private fields */);

Semaphore handle.

This handle is used to interact with semaphores created by the driver implementation.

Implementations

impl SemaphoreHandle

pub fn new(kind: SemaphoreKind) -> Self

Creates a new semaphore instance.

kind specifies the type of semaphore to create.

• Use SemaphoreKind::Counting to create counting semaphores and non-recursive mutexes.
• Use SemaphoreKind::RecursiveMutex to create recursive mutexes.

pub fn leak(self) -> SemaphorePtr

Converts this object into a pointer without dropping it.

pub unsafe fn from_ptr(ptr: SemaphorePtr) -> Self

Recovers the object from a leaked pointer.

Safety

• The caller must only use pointers created using Self::leak.
• The caller must ensure the pointer is not shared.

pub unsafe fn ref_from_ptr(ptr: &SemaphorePtr) -> &Self

Creates a reference to this object from a leaked pointer.

This function is used in the esp-radio code to interact with the semaphore.

Safety

• The caller must only use pointers created using Self::leak.

pub fn take(&self, timeout_us: Option<u32>) -> bool

Increments the semaphore’s counter.

If a timeout is given, this function blocks until either a semaphore could be taken, or the timeout has been reached. If no timeout is given, this function blocks until the operation succeeds.

This function returns true if the semaphore was taken, false if the timeout was reached.

pub fn give(&self) -> bool

Increments the semaphore’s counter.

This function returns true if the semaphore was given, false if the counter is at its maximum.

pub fn try_give_from_isr( &self, higher_prio_task_waken: Option<&mut bool>, ) -> bool

Attempts to increment the semaphore’s counter from an ISR.

If the counter is at its maximum, this function returns false.

If the flag is Some, the implementation may set it to true to request a context switch.

pub fn current_count(&self) -> u32

Returns the current counter value.

pub fn try_take(&self) -> bool

Attempts to decrement the semaphore’s counter.

If the counter is zero, this function returns false.

pub fn try_take_from_isr( &self, higher_prio_task_waken: Option<&mut bool>, ) -> bool

Attempts to decrement the semaphore’s counter from an ISR.

If the counter is zero, this function returns false.

If a higher priority task is woken up by this operation, the higher_prio_task_waken flag is set to true.

Trait Implementations

impl Drop for SemaphoreHandle

fn drop(&mut self)

Executes the destructor for this type.